This disclosure relates generally to the field of management of information technology (IT) services. More particularly, but not by way of limitation, it relates to a technique for improving the reconciliation of resources in an ITIL®-based (Information Technology Infrastructure Library) Configuration Management Database (CMDB). (ITIL is a registered trademark of The Lords Commissioners of Her Majesty's Treasury acting through The Office of Government Commerce and Central Computer and Telecommunications Agency, United Kingdom.) ITIL-based CMDBs are emerging as a prominent technology for enterprise management software.
In enterprise systems management, data about IT business entities such as servers and applications are generally spread across several repositories, known as Management Data Repositories (MDRs). This data is made available to software applications through various standard and non-standard mechanisms such as Structured Query Language (SQL) and/or other proprietary programming interfaces.
The usefulness of these CMDBs is dependent on the quality, reliability, and security of the data stored in them. A CMDB often contains data about managed resources known as Configuration items (CIs). In general, CIs correspond to real-world elements, components, or objects. ITIL version 3 defines a CI as “Any Component that needs to be managed in order to deliver an IT Service. Information about each CI is recorded in a Configuration Record within the Configuration Management System and is maintained throughout its Lifecycle by Configuration Management. CIs are under the control of Change Management. CIs typically include IT Services, hardware, software, buildings, people, and formal documentation such as Process documentation and [Service Level Agreements].”
The CMDB serves as a point of integration between various 11 management processes. Data from multiple sources often needs to be managed directly or by reference in commercial CMDBs. As different discovery processes may encounter the same object, it is important to identify such situations, and then merge and/or consolidate the information provided by the different processes for each object to avoid creating duplicate objects. This process is often called “reconciliation” or “resource reconciliation,” and is described more fully in the document entitled, “BMC Atrium CMDB 7.6.00: Normalization and Reconciliation Guide,” which is hereby incorporated by reference in its entirety.
Resource reconciliation processes typically consist of two primary operations: (1) identifying instances of objects of the same type, and (2) merging those instances that can be determined to refer to the same real world object. Instances identification is usually based on specific predefined rules considered in a specific priority order. Typically, a first rule is examined for an unidentified CI and if no match is found, the next rule in the list is tested, continuing until a match is found, or no more rules remain in the list. If none of the rules match, the CI can be auto-identified by assigning it a new identification property (Reconciliation ID) or left for manual identification. Auto-identification can lead to potential duplicates of CIs in the CMDB and is generally not recommended for ongoing resources reconciliation. Instead, most unidentified instances are in practice flagged for manual identification.
Manual identification is very time consuming and may need to be performed repeatedly. Because CMDBs tend to contain large numbers of CIs, in many cases containing 1,000,000 or more CIs, the amount of time needed for manual identification can be very large. Some studies suggest that about 20 percent of CIs have to go through manual identification. At 10 minutes per instance, manually identifying 200,000 instances out of 1,000,000 would require over 33,000 hours.